a) Illustrate the operation of a NMOS transistor in the saturation region using the IDS–VDS characteristic curve and derive its current equation. b) Calculate the drain current (IDS) for an NMOS transistor operating in saturation, given the following parameters: VGS=3.5V, VT = 1.2V, k′=130μA/V2 and W/L= 9. c) An NMOS transistor has W/L=9, VGS=2.8V, VT=1.2V, k′=130μA/V2, λ=0.05. Plot the output characteristics with a DC sweep of VDS from 0 V to 6 V at fixed VGS and evaluate how channel length modulation (with λ) affects the drain current in saturation region. Estimate the output resistance ro and discuss its influence on voltage gain. If μp=0.48μn what must be the PMOS device W/L to provide the same NMOS on-resistance. Assume Vtn=|Vtp|.